Epilobium tetragonum – Square-stalked Willowherb
Square-stalked Willowherb is one of those common but much overlooked plants not helped by the fact that it is one of several similar species that can be found in gardens and waste land. Square-stalked willowherb has an erect, hairless stem with four conspicuous raised ridges running down it, hence the name. The flowers are pink with four notched petals, eight stamens and an undivided, club shaped stigma. It can be confused with the closely related short-fruited willowherb but that plant has broader leaves and glandular hairs on the calyx.
|Type||Seeds per gram||Origin||Ordering|
|Wayside perennial||16000||Somerset||Order this species|
Square-stalked Willowherb is a native perennial of cultivated or waste ground both damp and dry and can be found in gardens, quarries and pits and woodland margins. I have had it growing in a rough area of my garden where I found a number of Elephant Hawk Moth caterpillar (Deilephila elpenor) feeding off it.
Easily established form seed sown in the autumn or spring.